STATS Assignment 40 MCQs

QUESTION 1
1. Determine P(-1.3 < Z < 0.16) for a standard normal distribution. A. 0.3396 B. -0.4668 C. -0.5332 D. 0.9032 E. 0.4668 2.5 points QUESTION 2 1. An academic advisor wants to predict the typical starting salary of a graduate at a top business school using the GMAT score of the school as a predictor variable. Some results from a simple linear regression of SALARY versus GMAT are shown below. b0 =-920400 b1 = 228 Predict the starting salary for a graduate who scored a 650 on the GMAT. A. $92,040 B. $66,700 C. $59,826 D. $56,160 2.5 points QUESTION 3 1. Fund 1 Fund 2 Fund 3 Fund 4 January 15 15 24 23 February 12 13 15 24 March 11 10 13 24 April 18 5 9 24 May 16 19 19 22 June 11 10 13 25 Fund 1 Fund 2 Fund 3 Fund 4 Mean 13.83333 12 15.5 23.66667 Standard Error 1.194897 1.966384 2.156386 0.421637 Median 13.5 11.5 14 24 Mode 11 10 13 24 Standard Deviation 2.926887 4.816638 5.282045 1.032796 Sample Variance 8.566667 23.2 27.9 1.066667 Kurtosis -1.81002 0.14343 0.25475 0.585938 Skewness 0.38819 0.032216 0.714533 -0.66567 Range 7 14 15 3 Minimum 11 5 9 22 Maximum 18 19 24 25 Sum 83 72 93 142 Count 6 6 6 6 2. Assuming an approximately normal distribution of return rates for Fund 4, we would expectAPPROXIMATELY 95% of the monthly return rates for Fund 4 to be in which of the following intervals? A. (20.57, 26.77) B. (21.6, 25.73) C. (22.63, 24.70) D. (23.25, 24.07) E. (22, 25) 2.5 points QUESTION 4 1. The time to complete a set of homework problems has a normal distribution with mean 42 minutes and standard deviation 9 minutes. One would expect 10% of students to complete their homework in more than ______ minutes. A. 53.5 B. 45.6 C. 43.4 D. 55.0 E. 1.28 2.5 points QUESTION 5 1. X P(X) 0 .08 1 .25 2 .38 3 .19 4 .08 5 .02 2. What is the probability that a household has more than 2 televisions? A. 0.38 B. 0.67 C. 0.33 D. 0.29 E. 0.71 2.5 points QUESTION 6 1. A random sample of eleven college students were surveyed and asked what brand of laptop they use and how long the battery lasted after the last full charge: Laptop Brand: Samsung, Dell, HP, Apple, Dell, HP, Dell, Toshiba, Dell, HP, Apple Battery Life (hours): 9, 6, 4, 9, 6, 3, 8, 10, 9, 5, 8 Assuming this data reflects all students: What would be the mean time the batteries lasted since the last full charge (in hours)? A. 7 B. 8 C. 9 D. 10 E. 7.5 2.5 points QUESTION 7 1. A study has shown that 30% of all students taking finance at Bellaire College fail the first exam. A random sample of 12 students taking finance at Bellaire College is selected. On average, how many students would you expect to fail the first finance exam? A. 8.4 B. 2.52 C. 1.59 D. 3.6 E. 1.90 2.5 points QUESTION 8 1. An educator is interested in the average amount of time that children watch television. Fifteen children were randomly sampled and the amount of time spent (in hours) watching TV per week is obtained. Use the printout below to answer the following question: TIME (hours) 15 5 Mean 9.86666667 7 Standard Error 1.447055 0 Median 10 9 Mode 5 14 Standard Deviation 5.6044 10 Sample Variance 31.409524 5 Kurtosis -0.161054 11 Skewness 0.0701961 21 Range 21 16 Minimum 0 12 Maximum 21 13 Sum 148 8 Count 15 2 Confidence Level(90.0%) 2.5487127 2. 3. Find the upper bound (to the nearest hundredth) of the 90% confidence interval for µ. A. 2.55 B. 11.81 C. 12.70 D. 11.31 E. 12.42 2.5 points QUESTION 9 1. The time to complete a set of homework problems has a normal distribution with mean 42 minutes and standard deviation 9 minutes. For a random sample of 36 students, find the probability that the SAMPLE MEAN completion time is greater than 45 minutes. A. 0.4772 B. 0.1293 C. 0.3707 D. 0.0228 E. 0.9772 2.5 points QUESTION 10 1. A professor wants to analyze the number of hours students spent online during the weekend and their scores on a test the following Monday. Part of the regression output appears below. Coefficients Standard Error t Stat P-value Intercept 93.97 4.52 2.77 0.050693 Test Score -4.07 0.86 -4.73 0.008048 R Square 0.69105342 Determine the value of the test statistic that the manager used to test whether test score is a useful predictor of performance. A. -4.07 B. 2.77 C. 93.97 D. 4.52 E. -4.73 2.5 points QUESTION 11 1. An academic advisor wants to predict the typical starting salary of a graduate at a top business school using the GMAT score of the school as a predictor variable. Some results from a simple linear regression of SALARY versus GMAT are shown below. b0 =-920400 b1 = 228 Set up the null and alternative hypotheses for testing whether GMAT is a useful predictor of SALARY. A. Ho : ?1 = 228 vs. Ha : ?1 ? 228 B. Ho : ?1 ? 0 vs. Ha : ?1 > 0

C.

Ho : ?1 = 0 vs. Ha : ?1 ? 0

D.

Ho : ?1 = 228 vs.
Ha : ?1 = 228

2.5 points
QUESTION 12
1.
A
travel agent would like to estimate confidence intervals for the average price
of a hotel room during the summer in a resort community. The agent takes a
random sample of 16 hotels from the community, and finds that the mean price of
regular room is $115 with a sample standard deviation of $30. Assume the
population of prices is normally distributed.
Find the lower bound
(to the nearest hundredth) for a 95% confidence interval for ?.

A.

100.30

B.

99.02

C.

102.66

D.

113.13

E.

101.85

2.5 points
QUESTION 13
1.

Fund
1

Fund
2

Fund
3

Fund
4

January

15

15

24

23

February

12

13

15

24

March

11

10

13

24

April

18

5

9

24

May

16

19

19

22

June

11

10

13

25

Fund 1

Fund 2

Fund 3

Fund 4

Mean

13.83333

12

15.5

23.66667

Standard Error

1.194897

1.966384

2.156386

0.421637

Median

13.5

11.5

14

24

Mode

11

10

13

24

Standard Deviation

2.926887

4.816638

5.282045

1.032796

Sample Variance

8.566667

23.2

27.9

1.066667

Kurtosis

-1.81002

0.14343

0.25475

0.585938

Skewness

0.38819

0.032216

0.714533

-0.66567

Range

7

14

15

3

Minimum

11

5

9

22

Maximum

18

19

24

25

Sum

83

72

93

142

Count

6

6

6

6

2.
Consider
the January monthly returns for Fund 1 and Fund 2. Relative to their own
fund, which January return had the better performance?

A.

Fund
1

B.

Fund
2

C.

They
were the same

D.

cannot
be determined

E.

2.5 points
QUESTION 14
1. A patient is tested for TB at a medical clinic. Consider the hypotheses:

Ho: The patient does not have TB
Ha: The patient has TB

When does a
Type I error occur?

A.

The test gives a
positive result (the patient has TB) when the patient actually has TB

B.

The test gives a
positive result (the patient has TB) when the patient does not have TB

C.

The test gives a
negative result (the patient does not have TB) when the patient actually has
TB

D.

The test gives a
negative result (the patient does not have TB) when the patient does not have
TB

2.5 points
QUESTION 15
1.
A
market research analyst believes that the average weekly household expenditure
on groceries in Pearland is $125. Assume that the weekly household expenditures
are normally distributed. In setting up the hypotheses to test the analyst’s
belief, she obtained a test statistic value of z = 1.45
Based on the results
of the hypothesis test at the 10% level of significance, which of the following
is a correct conclusion?

A.

There is sufficient
evidence to conclude that the average weekly household expenditure on
groceries in Pearland is $125.

B.

There is sufficient
evidence to conclude that the average weekly household expenditure on
groceries in Pearland is significantly different from $125.

C.

There
is not sufficient evidence to conclude that the average weekly household
expenditure on groceries in Pearland is significantly different from $125.

2.5 points
QUESTION 16
1.
An
economist claims that the average Hispanic owned business generates revenues of
less than $70,000 annually. A random survey of 10 Hispanic owned businesses
revealed an average annual revenue of $58,600 with a standard deviation of
$18,000. Assume a normal population. We wish to test the economist’s claim, at
a 10% significance level.
Based on the data and
this hypothesis test, state the conclusion at a 10% level of significance.

A.

There is sufficient
evidence that the average annual revenue for Hispanic owned businesses is
less than $70,000.

B.

There is sufficient evidence
that the average annual revenue for Hispanic owned businesses is less than
$70,000.

C.

There is sufficient
evidence that the average annual revenue for Hispanic owned businesses is
more than $70,000.

2.5 points
QUESTION 17
1.
A
study has shown that 30% of all students taking finance at Bellaire College
fail the first exam. A random sample of 12 students taking finance at Bellaire
College is selected.
Find the probability
that less than 5 students will fail the first finance exam.

A.

0.2764

B.

0.8821

C.

0.7236

D.

0.1179

E.

0.1585

2.5 points
QUESTION 18
1. The time to complete
a set of homework problems has a normal distribution with mean 42 minutes and
standard deviation 9 minutes.
Find the probability
that a randomly selected student will complete the homework problems in
less than 30 minutes.

A.

0.4082

B.

0.0918

C.

0.4032

D.

0.9082

E.

0.133

2.5 points
QUESTION 19
1. The stem-and-leaf diagram below displays the number of vacation
days taken in 1997 by a sample of
40 employees of an electronics company.

Stem
Leaves

0 00123334456889 Stem
unit = ten

1
000111134456

2
0000123468

3
001

4
3

Referring to the stem-and-leaf
display above, what PERCENTAGE of employees took less than 30 vacation
days?

A.

4

B.

90

C.

5

D.

10

E.

36

2.5 points
QUESTION 20
1. A study is being planned to estimate the mean number of inches
that trees will grow per year in a forest.
From previous studies, it is known that the growth is normally distributed and
the population standard
deviation is 0.80 inches. The analysts wish to have 90% confidence and want the
estimate to be within
0.20 inch. What size sample is needed for this study?

A.

43

B.

27

C.

44

D.

7

E.

43.3

2.5 points
QUESTION 21
1.
An
economist claims that the average Hispanic owned business generates revenues of
less than $70,000 annually. A random survey of 10 Hispanic owned businesses
revealed an average annual revenue of $58,600 with a standard deviation of
$18,000. Assume a normal population. We wish to test the economist’s claim, at
a 10% significance level.
Calculate the value
of the test statistic.

A.

2.003

B.

-0.633

C.

-2.003

D.

1.282

E.

1.372

2.5 points
QUESTION 22
1.

Fund
1

Fund
2

Fund
3

Fund
4

January

15

15

24

23

February

12

13

15

24

March

11

10

13

24

April

18

5

9

24

May

16

19

19

22

June

11

10

13

25

Fund 1

Fund 2

Fund 3

Fund 4

Mean

13.83333

12

15.5

23.66667

Standard Error

1.194897

1.966384

2.156386

0.421637

Median

13.5

11.5

14

24

Mode

11

10

13

24

Standard Deviation

2.926887

4.816638

5.282045

1.032796

Sample Variance

8.566667

23.2

27.9

1.066667

Kurtosis

-1.81002

0.14343

0.25475

0.585938

Skewness

0.38819

0.032216

0.714533

-0.66567

Range

7

14

15

3

Minimum

11

5

9

22

Maximum

18

19

24

25

Sum

83

72

93

142

Count

6

6

6

6

2.
3. The 50th percentile of Fund 3’s monthly returns would be ___________?
4.

A.

13

B.

15

C.

11.5

D.

14

E.

15.5

2.5 points
QUESTION 23
1. A random sample of eleven college students were surveyed and asked
what brand of laptop they use and how long the battery lasted after the last
full charge:

Laptop
Brand:Samsung, Dell, HP, Apple, Dell, HP, Dell, Toshiba, Dell, HP, Apple
Battery
Life (hours): 9, 6, 4, 9, 6, 3, 8, 10,
9, 5, 8

Assuming this data reflects all
students:
Assuming this data reflects all students at the college, what
brand of laptop would you expect the average
or typical student to own?

A.

Samsung

B.

HP

C.

Dell

D.

Apple

E.

Toshiba

2.5 points
QUESTION 24
1.
A
travel agent would like to estimate confidence intervals for the average price
of a hotel room during the summer in a resort community. The agent takes a
random sample of 16 hotels from the community, and finds that the mean price of
regular room is $115 with a sample standard deviation of $30. Assume the
population of prices is normally distributed.
Suppose a 90%
confidence interval for ? is (108, 122). State which of the following is a
correct
interpretation of the confidence interval by completing the following: We are
90% confident that_______

A.

the price for
regular room for the 16 hotels is between $108 and $122.

B.

the price for
regular room for all hotels in the community is between $108 and $122.

C.

the average
price for regular room for the 16 hotels is between $108 and $122.

D.

the average price
for regular room for all hotels in the community is between $108 and $122.

2.5 points
QUESTION 25
1. A survey was taken to determine how much time UHD students spend
doing homework per week. The random sample of UHD students resulted in the
frequency distribution shown below.

Time
(in hours) Frequency
0 and under
2
4
2 and under
4
6
4 and under
6
11
6 and under
8
18
8 and under
10
26
10 and under
12
5
What PERCENTAGE of the students studied 6 or more hours?

A.

11

B.

30

C.

0.16

D.

70

E.

0.3

2.5 points
QUESTION 26
1. The heights of women have a normal distribution with mean ? = 64
inches and VARIANCE of 4 inches. Let X = height of a woman and find P(X < 65). A. 0.3085 B. 0.1915 C. 0.6915 D. 0.5000 E. none of these 2.5 points QUESTION 27 1. Over the last 6 months, monthly returns (%) were tracked for 4 stock funds. Fund 1 Fund 2 Fund 3 Fund 4 January 15 15 24 23 February 12 13 15 24 March 11 10 13 24 April 18 5 9 24 May 16 19 19 22 June 11 10 13 25 Fund 1 Fund 2 Fund 3 Fund 4 Mean 13.83333 12 15.5 23.66667 Standard Error 1.194897 1.966384 2.156386 0.421637 Median 13.5 11.5 14 24 Mode 11 10 13 24 Standard Deviation 2.926887 4.816638 5.282045 1.032796 Sample Variance 8.566667 23.2 27.9 1.066667 Kurtosis -1.81002 0.14343 0.25475 0.585938 Skewness 0.38819 0.032216 0.714533 -0.66567 Range 7 14 15 3 Minimum 11 5 9 22 Maximum 18 19 24 25 Sum 83 72 93 142 Count 6 6 6 6 Which of these funds carries the most risk with respect to monthly returns? A. Fund 1 B. Fund 2 C. Fund 3 D. Fund 4 E. none of these 2.5 points QUESTION 28 1. A professor wants to analyze the number of hours students spent online during the weekend and their scores on a test the following Monday. Part of the regression output appears below. Coefficients Standard Error t Stat P-value Intercept 93.97 4.52 2.77 0.050693 Test Score -4.07 0.86 -4.73 0.008048 2. R Square 0.69105342 3. _________________is the percentage of variation in performance explained by test score. 4. 5. A. 86% B. 69.11% C. 4.07% D. 93.974% E. 0.69% 2.5 points QUESTION 29 1. An economist claims that the average Hispanic owned business generates revenues of less than $70,000 annually. A random survey of 10 Hispanic owned businesses revealed an average annual revenue of $58,600 with a standard deviation of $18,000. Assume a normal population. We wish to test the economist's claim, at a 10% significance level. State the null and alternative hypotheses for the test. A. H0: ? ? 58,600 Ha: ? > 58,600

B.

H0: ? =
70,000 Ha: ? ? 70,000

C.

H0: ? ?
70,000 Ha: ? < 70,000 D. H0: ? = 58,600 Ha: ? ? 58,600 E. H0: ? >
70,000 Ha: ? ? 70,000

2.5 points
QUESTION 30
1. A random sample of eleven college students were surveyed and asked
what brand of laptop they use and how long the battery lasted after the last
full charge:

Laptop
Brand: Samsung, Dell, HP, Apple,
Dell, HP, Dell, Toshiba, Dell, HP, Apple
Battery
Life (hours):9, 6, 4, 9, 6, 3, 8, 10, 9, 5, 8

Assuming this data reflects all
students:

The sample standard deviation of these battery lives, rounded to
the nearest hundredthm would be:

A.

5.40

B.

2.65

C.

7.00

D.

2.32

E.

2.22

2.5 points
QUESTION 31
1.
A
professor wants to analyze the number of hours students spent online during the
weekend and their scores on a test the following Monday. Part of the regression
output appears below.

Coefficients

Standard Error

t Stat

P-value

Intercept

93.97

4.52

2.77

0.050693

Test Score

-4.07

0.86

-4.73

0.008048

2.
R
Square 0.69105342
3.
At
the .05 level, the professor could conclude that the time spent online by
students over the weekend is a
useful predictor of test scores the following Monday.

A.

False

B.

True

2.5 points
QUESTION 32
1.
A
professor wants to analyze the number of hours students spent online during the
weekend and their scores on a test the following Monday. Part of the regression
output appears below.

Coefficients

Standard Error

t Stat

P-value

Intercept

93.97

4.52

2.77

0.050693

Test Score

-4.07

0.86

-4.73

0.008048

2.
R
Square 0.69105342
3.

4. What is the least squares regression equation?
5.

A.

y
= -4.07 + 93.97x

B.

y
= 93.97 – 4.07x

C.

y
= 93.97 + 4.52x

D.

y
= 4.52 + 0.86x

2.5 points
QUESTION 33
1. A random sample of eleven college students were surveyed and asked
what brand of laptop they use and how long the battery lasted after the last
full charge:

Laptop Brand: Samsung,
Dell, HP, Apple, Dell, HP, Dell, Toshiba, Dell, HP, Apple
Battery
Life (hours): 9, 6, 4, 9, 6, 3, 8, 10,
9, 5, 8

Assuming this data reflects all
students:
A ____________could be used to
display the frequencies of the battery life data, and a ___________could be
used to display the frequencies of the laptop brands.

A.

pie chart; histogram

B.

histogram ; bar chart

C.

bar chart; stem-and-leaf
display

D.

stem-and-leaf; histogram

E.

histogram; stem-and-leaf
display

2.5 points
QUESTION 34
1. A survey was taken to determine how much time UHD students spend
doing homework per week. The random sample of UHD students resulted in the
frequency distribution shown below.

Time
(in hours) Frequency
0 and under
2
4
2 and under
4
6
4 and under
6
11
6 and under
8
18
8 and under
10
26
10 and under
12
5
The class width is:

A.

10.00

B.

1.99

C.

12.00

D.

2.00

E.

100

2.5 points
QUESTION 35
1.

X

P(X)

0

.08

1

.25

2

.38

3

.19

4

.08

5

.02

2.
What is the expected number of televisions per household?
3.

A.

2.5

B.

2.8

C.

2.0

D.

3.0

E.

2.1

2.5 points
QUESTION 36
1. A survey was taken to determine how much time UHD students spend
doing homework per week. The random sample of UHD students resulted in the
frequency distribution shown below.

Time
(in hours) Frequency
0 and under
2
4
2 and under
4
6
4 and under
6
11
6 and under
8
18
8 and under
10
26
10 and under
12
5
What would be theAPPROXIMATE shape
of the frequency histogram?

A.

bell-shaped

B.

skewed to the left

C.

skewed to the right

D.

bi-modal

E.

none of these

2.5 points
QUESTION 37
1. A professor wants to
analyze the number of hours students spent online during the weekend and their
scores on a test the following Monday. Part of the regression output appears
below.

Coefficients

Standard Error

t Stat

P-value

Intercept

93.97

4.52

2.77

0.050693

Test Score

-4.07

0.86

-4.73

0.008048

R
Square 0.69105342
Interpret the SLOPE
of the least squares line.

A.

For every
additional hour spent online, the predicted test score increases by 93.97
points, on average.

B.

For every 1 point
increase in test score, the predicted time spent online decreases by 4.07
hrs, on average

C.

For every additional hour
spent online, the predicted test score increases by 4.52 points, on average.

D.

For every 1 point increase in
test score, the predicted time spent online increases by 93. min. on average.

E.

For every additional hour
spent online, the predicted test score decreases by 4.07 points, on average.

2.5 points
QUESTION 38
1.
An
economist claims that the average Hispanic owned business generates revenues of
less than $70,000 annually. A random survey of 10 Hispanic owned businesses revealed
an average annual revenue of $58,600 with a standard deviation of $18,000.
Assume a normal population. We wish to test the economist’s claim, at a 10%
significance level.
We would reject Ho if
the test statistic is:

A.

greater than 1.383

B.

less than -1.28

C.

less than -1.372

D.

less than -1.383

E.

greater than 1.645

2.5 points
QUESTION 39
1.
A
market research analyst believes that the average weekly household expenditure
on groceries in Pearland is $125. Assume that the weekly household expenditures
are normally distributed. In setting up the hypotheses to test the analyst’s
belief, she obtained a test statistic value of z = 1.45

Calculate the p-value
based on normal distribution.

A.

0.1470

B.

0.0287

C.

0.0735

D.

0.0574

E.

0.4265

2.5 points
QUESTION 40
1.
For a large survey of students,
the shape of this graph would most likely be described as :